Abstract
The antigenicity of two products of hydroxyapatite (HAP), supplied by two Japanese manufacturers, and three products of tricalcium phosphate (β-TCP), supplied by two Japanese and one American manufacturers, was studied by means of delayed type skin reactions in guinea pigs.
Skin reactions were elicited by injection of the ceramic into the dorsal skin 13 or 14 days after being immunized by intradermal injection of HAP or β-TCP into the dorsal flanks or footpads of guinea pigs.
After 24 hours. skin reactions were assessed by measuring the diameter of erythema and the degree of hemorrhage and induration.
The results were as follows:
1. Antigenicity was not detected for the HAP obtained from Asahi Optical Co., Ltd. and LION Co., Ltd.(self setting α-TCP) by means of skin reactions.
2. Antigenicity was not detected for the β-TCP obtained from Asahi Optical Co., Ltd. and Kyocera Co., Ltd.
3. In contrast, β-TCP from MITER, INC, USA (Synthograft®) induced delayed type hypersensitivity (DTH) 24 hours after antigen elicitation. The reaction appeared to be based on tuberculin and Jones-Mote types of reactions.
4. In the present study, Arthus reaction was not seen in any group of animals, indicating that HAP and β-TCP did not induce antibody formation.
